A county can include several towns and municipalities.
The county administration serves the county area. Its location in Bad Salzungen does not mean the county and town must have the same name. Thüringen is the federal state above it; Erfurt is that state’s capital.
Older maps may still show Eisenach as an independent city outside a county. On 1 July 2021 Eisenach joined Wartburgkreis and became a Große Kreisstadt. The official announcement says the county seat remained Bad Salzungen.
The other three answers
Each other option belongs to a different state.
Ammerland
Ammerland is a county in Niedersachsen. It does not name a Thüringen county.
Altötting
Altötting belongs to Bavaria. Its county administration is not governed by Thüringen municipal law.
Nordfriesland
Nordfriesland is a county in Schleswig-Holstein; its administrative seat is Husum.
Distinguish current administration from old maps.
Eisenach’s incorporation does not change the correct answer, Wartburgkreis. It explains why older documents may classify individual towns differently.
Population and the number of municipalities are not needed for this question. The essential match is between county name and federal state.
Merger with Eisenach · Wartburgkreis county administration ↗Wartburgkreis → Thüringen. County seat → Bad Salzungen.
Erfurt remains the capital of the whole state.
Three words for this question
- der Kreissitzcounty seat
- The town where the county administration is based.
- kreisfreiindependent of a county
- A city with this status does not belong to a county.
- die Eingliederungincorporation
- Bringing an area into another administrative unit.